DE 101 04 993 A1 describes a hand-held power tool for grinding or polishing, the electric motor of which acts on a grinding disk via a transmission. A switching device is located in the transmission, which may be used to select at least two types of grinding disk motions. One object of the present invention is to realize an oscillating grinding operation, and to enable the grinding disk to carry out an exclusively rotary motion in order to polish a work piece. To realize the oscillating grinding operation, an eccentric drive is provided, via which the rotational motion of the drive shaft is converted to an eccentric motion of the grinding disk.
It is possible for grinding devices of this type which include an eccentric drive to experience out-of-balance vibrations which reduce the handling comfort of the machine tool. It must be ensured that the oscillations and vibrations do not exceed a permissible level.